Postoperative pulmonary complications are not uncommon after liver transplantation. They can not only prolong the stay in intensive care unit and in hospital but also increase the morbidity and mortality rate. The underlying mechanisms are multifactorial, however, oxidative stress following hepatic ischemia reperfusion and the ensuing pulmonary leukocyte infiltration play an important part in the pulmonary complications. Various drugs and methods such as ischemic preconditioning have been used to lessen the production of oxidative free radicals following hepatic ischemia reperfusion. The choice of different anesthetic agents could aslo change the degree of production of oxygen species and antioxidant capacity during the operation.